Automatic telephone system



Aug. 16 1927. 1,639,089

E. JACOBSEN AUTOMATIC TELEPHONE SYSTEM Original Filed April 11, 1919 2 Sheets-Sheet i V126 Wmm ILLUEUZUF. EmMJECUbEEL-L 17 Fly Aug. 16, 1927. 1,639,089

E. JACOBSEN AUTOMATIC TELEPHONE SYSTEM Filed ril ts-Sheet 2 Ji l Patented Aug. 16, 1927.

um'rao STATES PATENT OFFICE.

EKIL JAOOBSEN, PLANDOME, NEW YORK, ASSIGNOR, BY KESNE ASSIGNMENTS, TO

AUTOMATIC ELECTRIC INC., OF CHICAGO, ILLINOIS, A CORPORATION 01' (DELA- WARE.

Application filed April 11, 1919, Serial Io. 888,288. Renewed September M, 1926.

My invention relates in generalv to an improved telephone system of the automatic type and more specifically-to a system in which means are provided for automatically 5 picking out an idle one of a plurality of subscribers lines any one of which will serve the purpose of the calling subscriber.

In systems in the past where automatic selection of a number of subscribers lines has been re uired, it has been the practice to use so ca led rotary connectors to finally connect with said lines. This rotary connector or selector connector combined the features of a selector and connectorin that on some levels of its banks it acted as a regular connector with subscriber controlled directive movement to pick out a certain line while on, another or other levels the lines would be grouped and when the wipers of the switch were directed to the first line of a group then the switch would be automatically rotated to the next line of the group in case the first line was busy. It will be seen that in such a system, each connector of a group of connectors which has access to one hundred lines, would have a multiple set of contacts for each line even though several of said lines have the same called number and belong to one party.

Among the objects of my invention are the provision of standard connector switches which have no automatic rotary or selecting action and in which there is only one set of contacts in the bank of each switch for each called number and which are so arranged that the same kind of service may be given, that is, the automatic picking out of any one of a plurality of lines, all of which have a single called number. In order to accornplish the above and other results, when a party is to be given a plurality of lines having one number, the multiples in the bank of the connectors which have access to this line are cut and connected to separate multipled sets of contacts in the banks of the line switches of the called lines. For instance, the contacts reached by calling the number in the first connector of the group are inul'tipled to corresponding sets of contacts in the line switches of all called lines of the group. The private contacts of the connectors of the group are so arranged that whenever one of the connectors picks out its only change is in the wirin set of contacts belon in to this group of lines, a circuit is close w ich causes the line switch of the first of this group of lines to start as a finder switch and pick out automatically the set of contacts in the connector. The line switch is arranged with a larger number of sets of contacts in its bank than usual so that on outgoing calls it still has accesstothe usual number of first selectors and always rotates past all contacts connected to the connector bank, while on an lncoming) call the contacts leading to selectors are usied so that only lines leading to the connectors may be selected. In this manner it will be seen that the connector switches are much simpler than in the past and the from the connector bank to the called lines and in the line switches.

Having ointed out the general features of my invention I will now explain the oper-. ation of the various'circuits and apparatus more in detail by referring to the accompanying drawings in which Fig. 1 shows a calling substation A having access through a line switch C to a connector H which is one of a group of connectors, perhaps ten in number, which have common access to called subscribers lines, some of which have allotted to them a single call number.

Fig. 2 shows a called station B which is a station on one of a plurality of lines common to a sin le number and any one of which will serve t e pur ose of the'calling subscriber. lines and its station, but I have shown the banks and their multiples and the cut ofi relays of two other stations which have the same call number.

I will now point out the operations of the various switches when the subscriber at substation A calls the number assigned to the subscriber B.

When the subscriber at substation A. removes his receiver a circuit is closed for the line relay 2 of the line switch G including the two sides of the line A in series and batteryr Relay 2 energizes to close a circuit for switching relay 3 and rotary magnet 4 in series and to also close a circuit for the mag net 4 direct to the private Wiper 5 at springs 6. Should the trunk be busy and ground I have s own only one of these standing then relay 3 will be shorted out and magnet 4 will Operate direct from ground on the wiper 5 to step the wipers to the next trunk line, also opening its own circuit at springs 7. This operation of magnet 4 continues until an idle trunk line is reached at which time no ground will be present on the wiper 5 and therefore relay 3 will no longer be shorted out andwill energize in series with the magnet 4 and to ground at springs 8. Relay 3 being of comparatively high resistance does not allow magnet 4 to energize at this time. Bela 3 operates to disconnect the line relay 2 an ground from the calling line and connects said line through the wipers of the switch C to a trunk line leading to an idle connector, which in this case will be assumed to be the connector H. As soon as the line is thus cut through a circuit is completed for the line relay 9 of the connector H in series with the line A. Relay 9 energizes to close a circuit for the slow relay 10, which supplies ground to the holding circuit of the line switch C, opens one point in the circuit of the release magnet 11, and prepares a circuit including the series relay 12 and the vertical magnet 13.

When the calling subscriber operates his calling device in accordance with the first digit of the called number, thecircuit of relay 9 is interrupted a corresponding number of times and said relay 9 operates to intermittently close the circuit of series relay 12 and vertical magnet 13. Magnet 13 is operated to step the wipers of the connector to the level of its bank in which is located the set of terminals leading to a set of multipled bank contacts in each of the line switches associated with the telephones having this call number in common. Relay 12 remains energized during this digit and causes all impulses after the first, to pass from ground through springs 14 and 15, springs 16 and 17, springs 19 and 18, springs 21 and 20, and through said relay and magnet to battery. After the impulses cease relay 12 falls back to prepare a circuit for the rotary magnet 22 and slow relay 23 through springs 21 and 24. Now when relay 9 operates in response to the impulses for the next digit it completes the circuit of said magnet and relay as follows: ground through springs 14 and 15, springs 16 and 17, springs 19 and 18, springs 21 and 24, springs 47, lower winding of relay 23, springs 26, and magnet 22 to battery. Magnet 22 therefore operates to step the wipers of the connector to the particular set of contacts assigned to the called group of lines. Should all of the lines accessible by means of this called number be busy then the bridge cut off relays 27, 28 and 29 of their respective line switches would be energized and the contact 30 engaged by the starting and test wiper 31 would be con nected through springs 32 and 33, springs 34 and 35, and springs 36 and 37 to battery through resistance 38. If this condition is met, then as soon as the slow relay 23 falls back after the operation of the rotary mag- 'net, a circuit will be completed from battery over said circuit through the resistance 38 and wiper 31 and its contact 30 through springs 39 and 40, upper winding of relay 41, springs 42 and 43, springs 44 and 45, and to ground through springs 46 of relay 10. Relay 41 therefore energizes to open the circuit of the rotary magnet at springs 47, connects the busy tone to the calling line at springs 48, opens the circuit of the private wiper 49 at springs 50, and closes a locking circuit for itself through its lower winding and over the above traced circuit to ground through springs 51 and 43. The calling subscriber must then hang up hisreceiver and call again.

Assume, however, that some one of the called lines is idle. Then when the connector H lands on the set of contacts and after slow relay 23 falls back a circuit is completed from ground through the said upper winding of relay 41 which is of low resistance, through springs 40 and 39, wiper 31, contact 30, conductor 52, springs 32 and 53, assuming the line B and its switch 0 to be idle, and through rotary magnet 54 to battery in series with the interrupter springs 55. The magnet 54 is of a higher resistance than the resistance 38, and the relay 41 is so adjusted that it will energize in series with said resistance 38 but will not energize in series with the magnet 54.

Magnet 54 however operates over this circuit to step its wipers in search of the set of contacts 56, 57, 30 and 58 which were seized by the connector H. It will be understood that should the line B and its line switch C have been busy at this time then the starting circuit instead of passing through springs 32 and 53 to the rotary magnet 54 would pass instead through the sprlngs 32 and 33, spring 34, and to the rotary magnet of the next idle switch.

Assuming that the wipers of the switch C are, when the switch is seized, standing on a set of contacts in their bank other than those seized by the switch H, then the operation of the magnet 54 causes the wipers 59, 60, 61 and 62 to be rotated until the wiper 61 meets the contact 63 thus completing a circuit from battery through the wiper cut on relay 64 of connector H, springs 50, wiper 49, contact 58, contact 63 and wiper 61, springs 65 and 66, which are closed at this time, springs 67 and 68, and through slow relay 69 to ground. Relay 69 upon energizing closes a series circuit for the relay 27 and the rotary magnet 54, and relay 64 of the connector opens the circuit of rotary magnet 22,

Lessons closes the line conductors tihrough to the wipers, open the starting circuit through conductor 52 so prevent further operation of the roiary magnec 54 of choline switcl; locks itself to ground through springs '70 and 45. Also a direct ground. is supplied be she wiper 49 through the springs and'lO the circuit for relay 69 is opened. Belay 27 alone energizesover the circuit clopedby iche operation of relay '89, relay 27 being of high resistance, and. operates to switch the l). so and through the called su' station and.

back-through the upper winding of ring cuic oil" relay 71 to battery and through the battery and ground back to the generator. I As soon as the called subscriber answers relay '31 char izes to disconnect the rin ing circuit and connect the back bridge re ay 72 t0 the called line. Relay 7 2 energizes in series with the called line and operates to reverse theconnections of the line relay 9 with re-- gard to the calling line for metering or anyv purpose. Conversation ma now proceed over the heavy conductors s own and upon its termination the connector will be released in the usualmanner, the release of the connector by the callin man removing ground from the holdin clrcuit of there ay 27 of the line switch which falls back to restore the circuits to "normal. The line switch, being of the typc which stands when idle pn the trunk lme last used, requires no reease.

Assume now that'some other subscriber similar toA were 'to initiate a call and finding the connectorH busy would therefore seize another connector similarto H which also has access to the same lines. As before pointed out, in a group of say ten connectors having access to 100 hues, instead of having all the bank contacts multipled as is the usual pracizice, certain of the contacts are not multiplied. That is, the line of substarion B has an individual set of contacts in each of the connectors of the group. There is, however, one contact for this 11118 in the connector H which is Inultipled to the corresponding contacts in all the other connectors of the group. This is the contact 30 associated with starting lead 52, which as shown is multipled in all the connector banks, so that if 91, assumed to be the directory number of line B, is called on any of the ten connectors, the wiper 31 or its correspending-wiper in one of the other switches and 67, an

As all the private contacts engaged by wiper will always connect with this lead to stars the first idle switch. 7

It, will be understood that the banks oi. the line switches Cl, H, G, can, have their banks not only sets of contacts which are connected to the connector: bank, but also sets similar to 80, 81, and 82 which lead to connectors or selectors for outgoing calls from'the line B and other lines of. the same group. As explained, when a line switch acts as a finder on an incoming call all leads to the selectors are busy to the line switches,

as the wiper 61 of the line switch (3 for instance acts as the test. wiper in this case and the wiper 61 in passing over the test contact 84 will not find battery as it must in ordcrto stop the switch. New on an outgoing call from any of the lines such-as B, the operation as'follows:

Assume the line B to be making a calL.

When the receiver is removed the line relay 85 energizes in series with the line in the usual manner to close a series circuit for relay27 and magnet 54 and also closes the springs 67, 86 and 87, thus closing a direct circuit for magnet 54 through springs 86 and 87 to the private wi or 60 and through springs 86 springs 66 and 55 to wiper 61.

60 which are associated with the connector banks are grounded, relay 27 will be shorted .be present on the contact 84 and as contact 90 1s open relay 27 will be no longer shorted out but will operate to disconnect the line relay 85 and connect the line B through to the switch seized. Ground will then be supplied to contact 84 from the switch seized, to hold relay 27 energized.

It will be seen therefore that I have provided novel andimprove'd means for allowing a calling subscriber to call a certain digit, operate a connector to one set of its contacts and have a selection of a number of lines allotted to the called subscriber. It will be understood that my invention applies toa larger system as well as to that shown, in wh ch one or more selectors are inserted between the line switch C and the connector H.

Having fully described and ascertained the features and aspects of my invention, what I consider to be new and desire to have protected by Letters Patent will be pointed out in the appended claims.

What I claim as my invention is 1. In a tale hone system, lines, an automatic switch or each line, trunk lines accessible to each of said switches, and means for operating a switch to automatically select one of said trunks when a call is extended lltl llll

from one of said lines and to automatically operate the first idle one of said switches to select one of said trunks when one of said lines is called to complete the connection from the calling subscriber to the line associnection therefrom to the line associated with.

the operated line switch.

3. In a telephone system, lines, an automatic switch for each line, incoming and outgoing switches associated therewith, means for controlling each automatic switch over the associated line to seize an outgoing switchwhen the line is calling, and means whereby the first idle one of said automatic switches may be controlled from an incoming switch to seize the said incoming switch when a call is being extended to one of the lines.

4. In a telephone system, lines, an auto matic switch for each line, incoming and outgoing switches associated therewith, means for controlling each automatic switch over the associated line to seize an outgoing switch when the line is calling, means whereby the first idle one of said automatic switches may be controlled from an incoming switch to seize said incoming switch when a call is being extended to one of. the lines, and means for preventing connection with an outgoing switch when an automatic switch is operated automatically from an incoming switch and for preventing connection with an incoming switch when an automatic switch is controlled from its associated line.

5. In a telephone system, a plurality of subscribers lines, an automatic switch for each line, said switches operated from their associated lines to extend connections therefrom, a plurality of other automatic switches having access to said lines in common, and a common starting lead for all of said first switches accessible to each of said other switches for causing the operation of any of said first switches to complete a connection from one of said other switches to one ofsaid lines.

6. In a telephone system, a plurality of subscribers lines, a switch individual to each line, means for operating the associated switch when a call is initiated by one of said. lines to automatically select an idle trunk, and means for operating the first idle one of said switches when another line is calling to one of said first lines whereby an idle one of said lines is connected to the calling line.

7. In a telephone system, a plurality of aesaoee cuit, said circuit including a wiper of said connector and the motor magnet of the finder, and means in said connector for closing said circuit.

8. In a telephone system, a plurality of lines extending to the same point and having a common call number, a finder switch individual to each line, a link circuit comprising line and test contacts'at one end permanently connected, respectively, to line and test contacts at the other end, a connector and means for operating it in accordance with said call number to connect with the contacts of one end of said link circuit, and means in said connector for operating one of said finders to connect with the said contacts at the other end of said link circuit.

9. In a telephone system, a plurality of lines extending to the same point and having a common call number, an individual switch for each line, trunk lines assessible to said switches, means for operating the associated individual switch when one of said lines is calling to select one of said trunk lines, a group of connectors, a link circuit accessible to each connector and individual thereto, all of said link circuits being aocessible to said individual switches in common, means for operating one of said connectors responsive to said call number to connect with its associated link circuit at one end thereof, and means for then operating one of said individual switches to connect with the link circuit in use at the other end thereof.

10. In a telephone system, a group of finder switches each having a motor magnet, an operating conductor normally connected to the motor magnet of the first finder switch, starting means for connecting a source of current to said conductor to variably operate the first finder, and means in each finder except the last for transferring said conductor to the next finder, whereby all-of said finders may be operated over said conductor.

11. In a telephone system, a plurality of finders, a starting conductor for said finders, means for placing a starting potential on said conductor at any one of a plurality of points, and means for preventing said means from placing an additional starting potential on said conductor when said conductor has a starting potential on it.

12. In a telephone system, a line, a switch individual to said line, two test wipers in said switch, an incoming trunk for completing connections to said line, outgoing trunks for extending connections from said line, means for operating said switch to test and seize either said incoming trunk or an idle one of said outgoing trunks, and means whereby only one of said test wipers is used for testing during the operation of said switch when the switch is operated to seize said incoming trunk and both said wipers are used for testing during the operation of said switch when the switch is operated to seize an idle outgoing trunk.

13. In a telephone system, a switch, said switch having access to outgoing and incoming trunks, means for operating said switch to either seize an idle one of said outgoing trunks or a predetermined one of said incoming trunks, two test wipers in said switch, and means for using only one of said wipers or both of said wipers for testing purposes dependent upon whether the switch is operated to select an outgoing trunk or a predetermined incoming trunk.

14. In a telephone system, a switch means for starting the operation of said switch from two different points, two test wipersin said switch, and means dependent on the point from which the operation of said switch is started for determining whether only one test wiper or both test wipers are to be used for testing purposes during the operation of said switch.

15. In a telephone system, a switch, said switch adapted to be operated as a line switch to automatically seize an idle outgoing trunk or as a finder to find a predetermined incoming trunk, two test wipers in said switch, and means for testing with only one wiper when the switch is operated to find and connect with said incoming trunk and for testing with both wipers when the switch is operated to select and connect with an idle one of said outgoing trunks.

16. In a telephone system, a line switch, a motor magnet in said switch for operating said switch, a line relay in said switch for starting the operation of said switch, acutoif relay in said switch for controlling said line relay, two test wipers in said switch, and

a circuit for said motor magnet including two branches, one of said branches including contacts -on the line relay, normally closed contacts on said cut-off relay, and one of said wipers, the other of said branches including contacts on said line relay and the other of said wipers.

17. In a telephone system, a line, an automatic switch, an incoming and an outgoing switch, means controlled from said incoming switch for causing said automatic switch to operate and connect with said incoming switch when a call is extended to saidrline,

and means controlled over said line for causing said automatic switch to continue to operate after it has connected with said incoming switch and connect with said outgoing switch, providing said last means is actuated before said automatic switch connects with said incoming switch.

18. In a telephone system, lines, a combination line and finder switch for each line, link circuits and trunk lines accessible to said switches, means controlled'over any one of said link circuits for causing an idle one of said switches to operate as a finder and find the link circuit over which the control is exercised when a call is extended in the direction of the lines, and means controlled by the initiation of a. call over the line associated with the switch being operated for causing the switch to change over and operate as a line switch and find anv idle trunk providing the call is initiatedover the line before the switch has found the link circuit.

19. In a telephonesystem, lines, a combination liiie and finder switch for each line, link circuits and trunk lines accessible to said switches, means controlled over any one of said link circuits for causing an idle one of said switches to operate as a finder and find the link circuit over which the control is exercised when a call is extended in the direction of the lines, means controlled by the initiation of a call over the line associated with the switch being operated for causing the-switch to change over and operate as a line switch and find an idle trunk providing the call is initiated over the line before the switch has found the link circuit, and means for then causing a difierent one of said switches to operate as a finder and find the link circuit.

20. In a telephone system, a plurality of subscribers lines, an automatic switch for each line, a magnet for each automatic switch controlled over the corresponding line for operating the associated automatic switch to extend connections from the corresponding line, a; plurality of other automatic switches having access to said lines in common, a common starting conductor accessible to each of said other switches, and means in each of said other switches for closing a circuit including said common starting conductor for any one of said magnets for causing the operation of the corresponding automatic switch to complete a connection from one of said other switches to the corresponding line.

Signed by me at New York, Bronx County, New York, this 7 day of April,

EMIL J ACOBSEN. 

